I received a package in the mail today. It contained a new little mini quad from Lumenier. The QAV250 looks to be a really amazing little take-anywhere fpv quad. The frame is machined from thick sheet G10. It feels like it can hold up to a heavy crash. The frame is light, but very rigid. It doesn’t have vibration dampening with a clean and dirty section as it’s big brothers (400, 500, 540G), but apparently it does reduce the vibrations. I am going to be installing the following components on this machine.

OpenPilot Revo using built-in OPLM (as the Rx)

RCX 1804-2400kv motors

Lumenier 12A SimonK ESC

Gemfan 5×3 props

Immersion RC 600mW 5.8GHz Vtx + Spironet CL

Sony 600TVL Board camera

Mobius Action Camera

I’ll be posting a build log here and hopefully on MultirotorUSA too. This build most likely won’t start until I complete the VulcanUAV Mantis.

Update: The build was too easy and I didn’t take any photos while building. Here’s a photo of it during the maiden.

Vulcan UAV Hexa Kit + Mantis Arms

Started building a new hexacopter this weekend. It’s replacing the Tarot T810. This frame seems much more spacious and easier find room for electronics. The “Mantis” arms are really good for keeping orientation as well as opening up the front for forward flight.

The Arduino Yun has been out for a little while. I didn’t really know what it was all about until I started using Temboo APIs for some of my projects. It intrigued me enough to buy one. I have really been excited to use an Arduino connected to a network and the Yun makes it very simple. What’s great is that I can create my own REST API to connect to it over a network. How great is that?

In the spirit of Christmas, I had spent some time last week working on a little personal project that I could use to get my kids excited about Santa and at the same time, modify their behavior if they were being bad. I was using a Raspberry Pi running a nodejs instance to listen for requests from an iPhone app. I’d send commands to the Pi, which would fade the color patterns on a BlinkM I had lying around. I connected the BlinkM to I2C and to the 3.3V rail since the RPi GIPO are only 3.3V capable. I got it working really well, but I needed to get a level shifter to get 5V to the BlinkM so the LEDs are a bit brighter. While I was looking to order the level shifter from Adafruit, I remembered that they had been carrying the Arduino Yun, so I decided to one instead of getting a level shifter.

Porting the project over to Yun was simple. Rather than using Nodejs, I used the Bridge Library. Essentially, this library connects the “arduino-side” of the Yun to the “linux-side.” You essentially listen for client connections on

http://arduino.local

and parse out the data from the path components. Very simple and straight forward, much like consuming any webservice. I struggled quite a bit trying to convert string data to byte

The project got a little bit smaller which is good. I want make a little wire harness so I can install the BlinkM into a translucent ball or star decoration. Then this will go on the tree.

I found this post hiding in my drafts folder. I guess I never posted it…Last summer I was out in Nevada for AUVSI. One early morning I headed out to Red Rock park with my friend Randy. Here’s a look at our little outing.

After being invited to demo OpenPilot gear at the Digital Harbor Foundation in Baltimore, MD, I have decided to starting doing some workshops with kids on building their first multirotor. My original plan was to make a PDF guide that the “students” could follow along with on iPads. After deciding that there should probably be some video content and some other tools like gear calculators, I decided to make it a native app. Of course I am going to need some photos, so I started by taking some photos of the building materials. This is going to be helpful for me in writing content for the “book” too.

It’s been a few months since I was sent a QAV540G kit from Tim at Lumenier. I was really excited to get it flying and decided to cannibalize my QAV500 to get in in the air. I decided to use the PDB, ESCs, motors and OpenPilot CC3D that so I would get a head start. I used the 540-sized arms and clean frame from the kit. After I completed the build, I realized I had a hard time getting the yaw locked in. Perhaps having the integrated brushless gimbal accentuated the issue and I never really took notice, but regardless, I had a tough time trying to tune it out.

You can see it here in this short clip at about the 40 second mark.

In order to address this, I started tuning the yaw by increasing my Yaw rate Kp and Ki gains, that didn’t do much in terms of keeping it locked in. It seemed that the slightest bit of breeze would toss it off axis. So, I increased it more, up to the point that the quad would “rev up” indicating that the Kp was too high. Even at that high rate, it still could be tossed off course by , what seemed like, a breath of air. Back to the drawing board…

Frustrated, I decided to put the 500-sized arms back on. I ran through the normal tuning process and still came up with the same problem. “Maybe if I swap out the CC3D for a Revo, it will work better?” Installed a Revo and still had the same yaw issue. Talk about painful. I decided to ask for the help of the multirotor tuning master, Enthlapy. Sure enough, he had the perfect advice: Just reduce the yaw rotation rates in the GCS and put some positive expo into your transmitter to compensate. It worked like a charm.

The brushless gimbal craze has reached a feverish pitch over the past year. Every time I do a search for brushless gimbals, I am bombarded with a new design from a new company or an updated design to an existing gimbal. I had bought a Tarot 5D2 gimbal with intent to only use it as a base for a brushless conversion. This gimbal is using the brushless conversion kit for Freefly gimbals. The kit was designed by divertom80 and is on Shapeways. I mount this under a Tarot T810 frame. I’d like there to be more range on the roll, but for simple, slow moves this works. I only have it stabilized on 2-axis for now.

It took quite a bit of “massaging” to get it working properly. That massaging was in the form of purchasing original FreeFly Cinestar parts. In hindsight, I should have started with the RCTimer clone of the CS gimbal, but this one was three-axis and mounted underneath the Tarot T810 I have. I may actually buy the CS dual adjustable tilt bar for maximum flexibility.

Here are the parts needed to get this Tarot gimbal up to speed with the CS version:

Inspired by @Patscherofel and bored with the “hard” mounted GoPro look at decided to try and mount my Jakub’s GoPro gimbal onto my tricopter. I’ve enabled camera stabilization to the gimbal and it’s working. I need to tune out some jittering I think, but over all I like the results.

I’ve since upgraded the “pitch’ servo to an HS-65HB which is much smoother than the HXT900 that I have on there now.